JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2018
·Vol. 29
·期 4
·757-765
·
IF 1.444
Li Xiaolan,Meng Dongling,Liu Ruiqi,Yang Yaling
A novel extraction technique combining dispersive liquid-liquid microextraction (DLLME) with magnetic solid-phase extraction (MSPE) is presented for pre-concentration of four primary aromatic amines (PAAs) released from azo dyes in paper samples prior to high performance liquid chromatography (HPLC). n-Octanol was used as the extractant and hydrophobic oleic acid modified Fe3O4 nanoparticles (Fe3O4@OA NPs) as an efficient adsorbent was applied to retrieve the PAAs-containing n-octanol in the DLLME step. Because of the rapid mass transfer associated with the DLLME and MSPE steps, fast extraction could be achieved. The main parameters affecting the efficiency of MSPE-DLLME procedure of PAAs were investigated and optimized. Under optimum conditions, the recoveries ranged from 79.6 to 88.5% and the limits of detection (LODs) were in the range of 0.21-1.16 ng mL-1 (S / N = 3). The intra-day precision (relative standard deviation (RSD)) was below 7.8% and inter-day RSD was less than 11%.
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Nanoscale
·
2018
·Vol. 10
·期 16
·7658-7665
·
IF 7.233
Longfei Ruan,Jin Lin,Wei Shen,Zhengtao Deng
Compositionally related cesium lead halide materials, such as CsPb2X5, have attracted great interest due to their considerable optoelectronic/optical properties as well as improved stability. Currently, CsPb2Br5 nanocrystals can be well-designed by tuning the ligands or precursor ratio, whereas, CsPb2X5 (with Cl− or I−) nanocrystals can only be obtained by the anion exchange method. Herein, we report a method to directly synthesize CsPb2X5 facilitated by thiol ligands. The morphology of CsPb2X5 can be designed as a nanowire. Importantly, the stability of directly synthesized CsPb2X5 nanowires is much improved when compared with the stabilities of the materials obtained by the anion-exchange method. We believe that this method will promote the application of 1D tetragonal CsPb2X5 in optoelectronics, optics and other fields.
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高影响因子
JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2019
·Vol. 43
·期 8
·e14003
·
IF 1.288
Zhong-Sheng Tang,Xin-An Zeng,Margaret A. Brennan,Zhong Han,Debao Niu,Yujia Huo
Characteristic aroma substances of cis-rose oxide imparts the odorant of “lychee-like,” while of citronellol is the precursor of it in lychee. The characterization of volatiles of lychee wine fermentation using headspace solid-phase microextraction gas chromatography-mass spectrometry combined with headspace gas chromatography-ion mobility spectrometry were done to regulate processing. Results indicated that the total of 97 volatiles (38 in common) were observed during fermentation, including 39 terpenoids, 5 alcohols, 22 esters, 4 acids, 7 alkenes, 4 ketones and ethers, 3 sulfur compounds and others. Losses of characteristic aromas mainly occurred during primary fermentation more than threefold decrease. The volatility of cis-rose oxide was stronger than citronellol, which implied that more gentle processing should be performed to protect lychee flavor. Cis-rose oxide was a mixture of monomer and dimer with unequal proportion, while citronellol was a monomer in lychee. The work provides important new information on aroma development during fermentation. Practical applications Fruit consumption, among which tropical fruit-based products have gained huge popularity in the recent years. The main high value-added processed products of lychee pulp are lychee wine and vinegar; however, the typical aroma always decreased or disappeared during fermentation. Therefore, this study aims at providing more information for product improvement and process development.
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ACS Applied Nano Materials
·
2019
·
IF 0
Qin Dai,He Zhao,Hongbin Cao,Yiqiu Wu,Zhi Sun,Xiaofei Meng,Tianyu Wang,Guangfei Yu,Jingyi Lin,Rong Hou
The green and low-cost preparation of carbon dots (CDs) with excellent fluorescence plays a key role in cell-imaging applications. Herein, we develop a green photochemical approach for fabricating CDs. The produced CDs can be used directly in lung cancer A549 cell imaging without any tedious post-treatments. As nontoxic and green alternatives to prevent pollution, fatty acids in sole aqueous media are the only reactants used to synthesize CDs. Furthermore, the green process of photoirradiation avoids harsh conditions, such as strong acids and bases, strong oxidants, and high temperatures and pressures. In addition, the by-products remaining in the aqueous environment are fatty acid dimers in the form of vesicles, which can also be recycled as gemini surfactant resources. We demonstrate that this green synthetic method for fabricating CDs is suitable for fatty acids with different chain lengths, and therefore, exhibits considerable universality. Fatty acids, as readily available green resources in nature, and the green and simple synthesis method without additional pollution provides a new approach and perspective for the green synthesis of CDs for bioimaging.
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Analytical Methods
·
2018
·Vol. 10
·期 41
·4978-4984
·
IF 2.073
Xing Huang,Kaipeng Zhang,Yanli Tong,Yongsheng Zhong,Zuanguang Chen
In this study, a gradient reverse phase high performance liquid chromatography combined with a capacitively coupled contactless conductivity detection (RP-HPLC-C4D) method for simultaneous determination of phospholipid and fatty glyceride in liposome was developed. After saponification, the fatty glyceride and two types of phospholipids were transformed into octanoic acid, palmitic acid and erucic acid, respectively, which were then separated and detected by RP-HPLC-C4D. The results showed good linearity in the range of 20–1000 μg mL−1 for octanoic acid and erucic acid and 10–1000 μg mL−1 for palmitic acid. The LODs of octanoic acid and palmitic acid reached 2.5 μg mL−1, and 10 μg mL−1 for erucic acid. The average recoveries of octanoic acid, palmitic acid and erucic acid were 100.2%, 102.9% and 101.4% (n = 9), respectively. The developed method could be effectively applied in the quality control and stability monitoring of liposome.
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FOOD AND AGRICULTURAL IMMUNOLOGY
·
2018
·
IF 2.568
Fengyin Liu,Zijian Chen,Yudong Shen,Yuanming Sun,Jinyi Yang,Hong Wang,Hongtao Lei,Zhenlin Xu
Immunoassay direct for 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ), the metabolite of furaltadone, based on a specific antibody was usually unavailable due to its small molecule weight. In this work, a hapten with a double bond and an active carboxyl group was designed and then conjugated to peptide dendrimer to obtain novel multiple haptens. The haptens and multiple haptens were coupled to bovine serum albumin as immunogens. Polyclonal antibodies showed binding to free AMOZ in a heterologous competitive indirect enzyme-linked immunosorbent assay were obtained. The assay showed IC50 (half maximal inhibitory concentration) of 4.1 μg/kg and limit of detection of 0.2 μg/kg for AMOZ. Recoveries of AMOZ from grass carp were tested from 83.1% to 117.0%, with the coefficient of variation below 12%. As no laborious derivatisation procedure was employed, the proposed assay should be useful for the screening of AMOZ for a large number of samples.
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JOURNAL OF SEPARATION SCIENCE
·
2017
·Vol. 41
·期 7
·1635-1643
·
IF 2.557
Dandan Ge,Yi Zhang,Yixiu Dai,Shumin Yang
Deep eutectic solvents are considered as new and green solvents that can be widely used in analytical chemistry such as microextraction. In the present work, a new dl- menthol-based hydrophobic deep eutectic solvent was synthesized and used as extraction solvents in an air-assisted dispersive liquid–liquid microextraction method for preconcentration and extraction of benzophenone-type UV filters from aqueous samples followed by high-performance liquid chromatography with diode array detection. In an experiment, the deep eutectic solvent formed by dl- menthol and decanoic acid was added to an aqueous solution containing the UV filters, and then the mixture was sucked up and injected five times by using a glass syringe, and a cloudy state was achieved. After extraction, the solution was centrifuged and the upper phase was subjected to high-performance liquid chromatography for analysis. Various parameters such as the type and volume of the deep eutectic solvent, number of pulling, and pushing cycles, solution pH and salt concentration were investigated and optimized. Under the optimum conditions, the developed method exhibited low limits of detection and limits of quantitation, good linearity, and precision. Finally, the proposed method was successfully applied to determine the benzophenone-type filters in environmental water samples with relative recoveries of 88.8–105.9%.
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高影响因子
Nanophotonics
·
2017
·Vol. 7
·期 2
·473-478
·
IF 4.492
Lihua Ye,Fangjie Li,Changgui Lu,Zhixiang Cheng,Guohua Hu,Yanqing Lu,Yiping Cui
The random laser from sheared dye-doped polymer-dispersed liquid crystal (DDPDLC) is investigated. As the emission intensity weakens, the threshold of random laser from DDPDLC increases from 2.0 mJ/pulse to 4.0 mJ/pulse, and the degree of polarization (DOP) increases from 0.1 to 0.78, obviously when the shear distance increases from 0 mm to 4 mm. As the liquid crystal droplets are gradually oriented in the shear direction caused by alignment direction of polymer chain and anisotropy of droplet shape, the scattering intensity perpendicular to the shear direction gradually decreases and that parallel to the shear direction gradually increases. The anisotropic absorption of the laser dye also plays a certain role as the shear distance is 0 mm. The controllable intensity and polarization degree of random laser have a huge potential for sensing applications.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 30
·7063-7075
·
IF 3.431
Wang Meng,Jiao Yang,Cheng Chunsheng,Hua Jianhao,Yang Yaling
A novel and sensitive method based on nitrogen-doped carbon quantum dots as a fluorescence probe coupled with magnetic solid-phase extraction (MSPE) purification for analysis of folic acid (FA) in human serum samples has been established for the first time. In the developed system, magnetic nanoparticles coated with hexanoic acid (Fe 3 O 4 @C 6 ) were synthesized by a one-step chemical co-precipitation method with good magnetic properties and dispersibility for sample purification, and it is better to be separated from the sample. High fluorescence nitrogen-doped carbon quantum dots (N-CQDs), simply prepared using a one-step hydrothermal method with nitrilotriacetic acid, could be selectively quenched by FA. Based on this phenomenon, a fluorescence assay was proposed for specific determination of FA. Various operational experiment parameters have been studied and optimized in detail. Under the optimum experimental conditions, the detection limit of the proposed method for FA was evaluated to be 0.5 nM (S/ N = 3), while the relative standard deviation (RSD) was 1.2% ( n = 6). Finally, the proposed method was applied for determination of trace levels of FA from human serum samples and quantitative recoveries were achieved within the range of 95.7–103.5%. All of the results showed that the proposed method had significant application in further research.
Schematic of synthesis of N-CQDs and schematic of suggested mode for analysis of folic acid (FA).
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Nanoscale
·
2017
·Vol. 9
·期 44
·17248-17253
·
IF 7.367
Yibing Xu,Qiang Zhang,Longfei Lv,Wenqian Han,Guanhong Wu,Dong Yang,Angang Dong
Discretely sized semiconductor clusters have attracted considerable attention due to their intriguing optical properties and self-assembly behaviors. While lead halide perovskite nanostructures have been recently intensively explored, few studies have addressed perovskite clusters and their self-assembled superstructures. Here, we report the room-temperature synthesis of sub-2 nm CsPbBr3 clusters and present strong evidence that these ultrasmall perovskite species, obtained under a wide range of reaction conditions, possess a specific size, with optical properties and self-assembly characteristics resembling those of well-known II–VI semiconductor magic-sized clusters. Unlike conventional CsPbBr3 nanocrystals, the as-synthesized CsPbBr3 nanoclusters spontaneously self-assemble into a hexagonally packed columnar mesophase in solution, which can be further converted to single-crystalline CsPbBr3 quantum nanoribbons with bright deep-blue emission at room temperature. Such a conversion of CsPbBr3 nanoclusters to nanoribbons is found to be driven by a ligand-destabilization-induced crystallization and mesophase transition process. Our study will facilitate the investigation of perovskite nanoclusters and offer new possibilities in the low-temperature synthesis of anisotropic perovskite nanostructures.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 23
·14486-14497
·
IF 3.269
Yuxian Wang,Ling Jiang,Ce Wei,Hongman Zhang
Fatty acids, composed of an amphiphilic carbon chain and a carboxyl group, are a simple class of anion surfactants when they are protonated in the presence of an alkali. They can form ion-pairing amphiphile molecules and self-assemble into different nanostructures, which can be widely applied. However, the phase transition of these nanostructures can be easily triggered by external conditions, such as pH, temperature, the addition of salts and so on. In this work, medium-chain fatty acids (MCFAs) containing 8–12 carbons were chosen as the objects for self-assembly with organic amino counter-ions, L-arginine. We investigated the effects of chain length, pH, temperature and solvent on the phase transition based on diagrams, which could be determined by freeze fracture transmission electron microscopy (FF-TEM) and polarizing microscopy observations (PMO) combined with rheological properties. The results showed that rich phase behavior was observed in the octanoic acid (C8:0) system. However, it was insensitive to changes in pH because of the lower hydrophobicity. In contrast, for decanoic acid (C10:0) and lauric acid (C12:0) systems, phase transition from the L1 phase (micelles) to the Lα phase (vesicles) was observed and they showed stimulus-response to the change of pH. At the same time, lauric acid was sensitive to temperature, which was ascribed to the higher Krafft point. Besides, when the solvent was replaced by glycerin, phase transitions occurred from vesicles to micelles in these three systems. We hope that this phase transition observed in the MCFA system will provide a good insight into drug delivery, material science, and other related areas.
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FOOD HYDROCOLLOIDS
·
2024
·
IF 11
Ke Zhang,Lai Jiang,Ru-Kang Chen,Yu Shi,Yu-Gang Shi,Yue-Wen Chen,Rammile Ettelaie,Ping Li
This study aims to construct a versatile film fabricated by gallic acid/octanoic acid-grafted-chitosan (GA/OA- g -CS) for high photodynamic antibacterial and antibiofilm efficacy with blue light (BL, 420 nm) irradiation. First, the GA/OA- g -CS conjugates were synthesized by a green radical-induced grafting reaction in the redox system composed of ascorbic acid/hydroxyl peroxide (AA/H 2 O 2 ). Then, the molecular structural and physicochemical characteristics of the conjugates, as well as the mechanisms of the free radical grafting reaction were further studied. Ascorbate radical ( Asc • − ) and hydroxyl radical (•OH) were produced in the AA/H 2 O 2 system, and •OH reacted with CS to produce CS macro-radicals (•CS). UV–vis, Fourier transform infrared, nuclear magnetic resonance spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis confirmed that GA/OA was attached onto CS through •OH. Notably, the films constructed by GA/OA- g -CS exhibited robust multi-modal functionalities, including intriguing bacteria-capturing and contact-killing, as well as BL-driven photodynamic sterilization, ascribed to the inherent merits based on the massive photoactive GA, hydrophobic and high membrane affinity of OA within the CS chains. As a result, the GA/OA- g -CS (2:1) film plus BL irradiation can efficiently eradicate Escherichia coli ( E. coli ), Staphylococcus aureus ( S. aureus ) and their biofilms. After BL irradiation for 30 min, the GA/OA- g -CS (2:1) film showed a reduction of 5.2 Log CFU/mL against E. coli . More importantly, the film with BL irradiation can efficiently not only inhibit the formation of biofilms but also jeopardize the matured biofilms. This research provides a potential platform and promises for applications in active and intelligent food packaging.
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